Zainab Moazzam1, Paul B Yoo1,2. 1. Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada. 2. Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada.
Abstract
AIMS: Percutaneous tibial nerve stimulation (PTNS) is an effective neuromodulation therapy for treating overactive bladder (OAB). The therapeutic effects are achieved by repeatedly applying electrical stimulation through a percutaneous needle electrode that is used to target the tibial nerve (TN). Anatomical studies indicate there can be multiple saphenous nerve (SAFN) branches located near the site of electrical stimulation, and therefore we investigated the possibility of evoking a bladder-inhibitory reflex by electrically activating the SAFN. MATERIALS AND METHODS: Acute experiments were conducted in 26 urethane-anesthetized rats. Changes in bladder contraction rate (BCR) and bladder capacity were measured in response to 10-min SAFN stimulation trials. Electrical pulses were applied at 25 µA and at stimulation frequencies between 2 Hz and 50 Hz. RESULTS: We report that SAFN stimulation at 20 Hz was most effective at reflexively decreasing the BCR (53.8 ± 5.4% from baseline) and also increasing the bladder capacity (145.8 ± 43.5% from baseline). In contrast, SAFN stimulation at other frequencies yielded inconsistent changes in bladder function. Carry-over effects were minimized by randomizing the sequence of SAFN stimulation trials and also by allowing the bladder to return to the baseline conditions. CONCLUSIONS: With notable changes in both the BCR and bladder capacity, our findings provide evidence of a novel bladder-inhibitory reflex in anesthetized rats that is mediated by the SAFN. Further work is needed to determine the clinical relevance of this neural pathway.
AIMS: Percutaneous tibial nerve stimulation (PTNS) is an effective neuromodulation therapy for treating overactive bladder (OAB). The therapeutic effects are achieved by repeatedly applying electrical stimulation through a percutaneous needle electrode that is used to target the tibial nerve (TN). Anatomical studies indicate there can be multiple saphenous nerve (SAFN) branches located near the site of electrical stimulation, and therefore we investigated the possibility of evoking a bladder-inhibitory reflex by electrically activating the SAFN. MATERIALS AND METHODS: Acute experiments were conducted in 26 urethane-anesthetized rats. Changes in bladder contraction rate (BCR) and bladder capacity were measured in response to 10-min SAFN stimulation trials. Electrical pulses were applied at 25 µA and at stimulation frequencies between 2 Hz and 50 Hz. RESULTS: We report that SAFN stimulation at 20 Hz was most effective at reflexively decreasing the BCR (53.8 ± 5.4% from baseline) and also increasing the bladder capacity (145.8 ± 43.5% from baseline). In contrast, SAFN stimulation at other frequencies yielded inconsistent changes in bladder function. Carry-over effects were minimized by randomizing the sequence of SAFN stimulation trials and also by allowing the bladder to return to the baseline conditions. CONCLUSIONS: With notable changes in both the BCR and bladder capacity, our findings provide evidence of a novel bladder-inhibitory reflex in anesthetized rats that is mediated by the SAFN. Further work is needed to determine the clinical relevance of this neural pathway.
Authors: Gregory M Holmes; Charles H Hubscher; Andrei Krassioukov; Lyn B Jakeman; Naomi Kleitman Journal: J Spinal Cord Med Date: 2019-09-26 Impact factor: 1.985
Authors: Shun Li; Xing Li; Katherine Theisen; Jeffery Browning; Bing Shen; Jicheng Wang; James R Roppolo; William C de Groat; Changfeng Tai Journal: Am J Physiol Renal Physiol Date: 2017-10-25
Authors: Robert F Hoey; Daniel Medina-Aguiñaga; Fahmi Khalifa; Beatrice Ugiliweneza; Sharon Zdunowski; Jason Fell; Ahmed Naglah; Ayman S El-Baz; April N Herrity; Susan J Harkema; Charles H Hubscher Journal: Sci Rep Date: 2021-02-08 Impact factor: 4.379
Authors: Robert F Hoey; Daniel Medina-Aguiñaga; Fahmi Khalifa; Beatrice Ugiliweneza; Dengzhi Wang; Sharon Zdunowski; Jason Fell; Ahmed Naglah; Ayman S El-Baz; April N Herrity; Susan J Harkema; Charles H Hubscher Journal: Sci Rep Date: 2022-02-08 Impact factor: 4.996